One of my viewers wrote a nice email talking in more detail about lithium battery issues and I thought I would repost it here: Hi, I just thought I'd respectfully chip in some thoughts on your new video. By way of background, I am one of the co-founders of QFE - a battery engineering startup in Hong Kong. We develop proprietary technologies for large battery systems to make them safer, more reliable, more energy dense and more cost effective for OEMs to deploy. Our team is comprised of mechanical, electrical and chemical engineers, and I have recommended your videos to the guys less inclined with electronics to watch in the past. I think one issue which you addressed very well is the fact that the inherent safety of a particular chemistry is less important than how the batteries are used. 100% agreed. Two issues I thought I'd point out: 1. 'Lithium polymer' isn't a specific chemistry, per se. The underlying cathode chemistry of 'lithium polymer' batteries is 'lithium-ion', which is a broad, umbrella term covering lithium + a combination of cobalt, manganese, nickel etc. Lithium polymer refers to batteries of 'lithium-ion' chemistries that are physically packaged in a pouch form factor. 2. Pretty much every battery chemistry out there has the potential to explode or catch fire or do both, if used incorrectly. Even lead acid batteries can explode too, as hydrogen - an explosive gas - can be produced as a side product. Pouch cells are as unprotected of a battery construction as battery constructions get. Sheets of active material loosely contained between two insulating sheets. As an analogy, that's like sticking petrol in plastic bag, tying a knot and using that in your project. Lithium iron phosphate batteries in pouch form can puff up and explode too (noting the distinction between an explosion and a fire). Lithium-ion batteries also come in small cylindrical constructions. These are incredibly safe, for four primary reasons: i) The outer casings are incredibly hard to compromise/pierce. Really, really hard. ii) The shape of the cell makes it difficult for objects to hit the cell perpendicularly; blows are typically, glancing. iii) Unlike pouch cells, all decent small, cylindrical li-ion batteries have a safety vent, which releases the internal pressure of a battery cell in a controlled way, if the pressure builds up to dangerous levels. iv) Decent, small, cylindrical batteries also build in a PTC, effectively disconnecting the battery from an electrical circuit if it gets too hot, hopefully preventing any further damage to the cell. We're fans of small, cylindrical lithium-ion cells for other reasons as well: cost, weight & volumetric energy density, availability etc. Hopefully this is helpful and not spammy. Do please be in touch with me if I can help in any way. Please keep up the great work with the videos - easily the clearest, most easy to understand electronics videos on the internet. Best regards, Brandon Brandon Ng CEO QFE qf-eng.com

I just finished watching all your basic electricity videos and I feel like I am finally beginning to actually grasp electrical units. I haven't heard it explained so well anywhere else, thank you so much.

NiCd cells are deprecated because cadmium is a problem in the waste stream and prohibited by RoHS. AFAIK SLA batteries are nowadays called VRLA (valve-regulated lead-acid). Battery capacity specifications in eBay advertisements are often exaggerated. Very useful video!

Nickel-cadmium are also very good at performing in very cold weather, have their output voltage quite stable during discharge (in contrast with for instance alkalines and lead-acid) and can put out serious currents (20A for a small AA battery!)! I love them!!

I absolutely love this channel... The videos are informative and fun to watch at the same time... thanks man....

you definitely have the most useful tech vids.

Very high production quality. Very informative. You just earned my sub!

That was supremely awesome and helpful. I've always wondered about the various battery types, including the oddballs like NiCd. Thank you for the video!

tutorial after battery options was a really good help, thanks

What an adorable intermission.

afrotechmod.............your explanation is really very awesome ......keep it up

Excellent tutorial,thanks

Awesome video! The "puffy-battery-if-discharged-too-low" issue with LiPo is something I learnt the hard way :-)

really cool video :) thanks for sharing it!

You only looked at rechargable batteries. For non rechargable stuff, most people use Alkaline or Zinc Carbon batteries, but for very long term operations (small self discharge), high energey density (very high), or operation in harsh temperatures, I would recommend looking into Lithium Thionyl Chloride (LTC) chemistry. It has a lot of advantages, and are on average 3-8 time better than alkaline in many applications (especially low power or periodic pulsed power situations). In fact they do have higher energy density than Lithium-ion or Lithium-polymer batteries. Also bundling Lithium-ion and LiPo batteries in one category is a mistake. They are quiet different, as the first one denote ones with liquid electrolyte, and second with polymer membrane. They do have vastly different properties in general.

Thank you for captioning your videos.

Nickel cadmium batteries are used quite a bit on aircraft because the batteries provide the starter motor with electricity. These are quite hefty starters and nickel cadmium batteries can provide consistent voltage till they are almost drained. However, many people are starting to go over to lithium ion.

Love your videos! very easy to understand even with my not high level of english, regards from Spain!

Another awesome video!

Beautiful!! learned a lot! Thanks!

Another great vid! Thanks!

Do you know of any good circuits that can charge NiMh batteries and automatically stop when finished? I was under the impression that it's quite hard to detect when the battery is full, but it would be super useful to permanently build them into projects rather than relying on an additional charger.

Excellent video Afrotech, it taught me exactly what it promised to teach. Thank you. As a suggestion for a future video, could you explain converting (modding) circuits from Alkaline/Ni-Cad-powered to Lithium-powered? As a simple example, an LED torch that runs on 3 AAA batteries - how to modify it to run on an 18650 cylindrical li-ion battery, bearing in mind that (so I've been told) using an Li-Ion could overheat the LED due to internal resistance/current differences. Thanks.

Thank you for this video!

Posted on the Hackaday blog! Congrats!

This was very helpful. Thanks

Great info. I always find your videos informative. Thanks.

For LiPo we never discharge under 3V in use but to damage it you have to discharge it under 2.5V. Ni-Mh batteries have memory effect!

Great guide.. Thanks!

excellent tutorial

Great guide

I've been watching a ton of videos trying to understand batteries. Your videos are by far the best I've seen. Trouble is, I'm still not fully understanding. So I really like the new "Soundboks 2" portable Bluetooth speaker, but the device will easily run me over $900. Money I don't have. I've decided I'd take it upon myself to build my own bluetooth speaker that could "somewhat" compete with the Soundboks for my own personal use & affordability. Anyway you could help??

Great video. Perhaps you could touch on NiFe batteries for home power storage?

YES! Thank you!

2:49 Quite glad to see a Romanian battery in a clip. :)

I like the intermission :)))

thanks for this video :)

great stuff!

Nice job

thumbs up for michael bay's explosion joke. i used regular Li-Ion 18650 cell for projects, it's quite good, cheap, and easy to get. more energy than Ni-MH like Eneloops, etc.

great tutorial.....can you please provide some insights on Lithium Titanate batteries as well, in comparison with the others mentioned in the video...thanks..

Never been this early to see your video!

Man, I love your channel so much.... I'm really tempted to become a patreon of your channel, but I have no money (for myself) at the moment :(

li-ion charger circuit tutorial pls :D Love your videos very informative and understandable :)

Great video. I have a question, why do lithium batteries commonly found in cellphones seem to get easily addicted if you don't fully use them before you recharge each time? I thought they didn't have that memory problem you mentioned. Thanks

More so than weight, I thought that overall energy density was the main driving factor behind Li-Po battery packs. It's not just that they're lighter, it's that they fit into a MUCH smaller form factor for the same amount of energy storage. This, to my knowledge, is why mobile device engineers prefer them.

The memory effect for NiCds does not really exist unless you consistently and always only discharge it to the same point (within 1% tolerance) many, many times. It was actually NASA that noticed this with drills they used for some missions. (They noticed that after many hundreds of cycles, the batteries mysteriously lost capacity to the point it they were being discharged to.) I believe it is also possible to undo it.

nice video ... interesting 👍

Afrotechmods what involves building own Li-ion cell charger? Would you do video about it? Do protection circuits on Web site you've provided are actually church and discharge protection circuits or just discharge?

Hi, Can you please shed more light on the different types of Lead Acid batteries. You are talking more about SLA's but we have the Tubular ones, the traditional ones which require distilled water top ups...., There is also a construction difference between the ones that are used for automobiles and ones used for power storage (Deep Discharge)

What about making a hybrid nickel cadmium battery could be good if they had a circuit that would not allow you to recharge it unless it was fully drained and the charger would lock it in until till it was fully charged, If someone needed to charge the battery while 1/2 charged the circuit would have a button to make it drain fast or recharge a 2nd battery attached with it as a reserve that would help in the efficiency. Also what about the super capacitors that some use for batteries with special circuits that act like batteries? Aren't those considered the best type since they say electric cars use them? I was wondering fi one of your videos has clues on how to make it which I kind of remember something like that when watching your voltage regulator videos.

I enjoy your videos - Thanks! Have you worked with any good alternatives to the battery? Batteries are almost always the "weak link" (most limiting variable) over time

good stuff

can you make a video on how to build a LiPo battery charging-discharging circuit?

Brilliant! I love your videos! Informative and entertaining, and I'm not even a cat person.

watt hours/gram you can actually get li-ion batteries that store nearly twice as much energy as li-po batteries. the down side is the low C rating on the li-ion.

What about super-capacitors for applications, such as replacing the car battery? According to some YT video that I watched, somebody replaced his old car battery, with a in-series bank of super-capacitors, it worked just fine, and it was a fraction of the size and weight of a car battery.

@4:40 expensive isn't a pro argument for the lithium cells :D anyway nice and informative video

intermission....hahah.. by the way, the video was really helpful...keep it up and i would like to see more of ur videos..

You forgot to cover the most popular ones (Li-ion). I know they are very similar to Li-Po, but you should have at least mentioned them ! Oh well, thanks anyways. :)

So I spent some time on batteryspace.com looking for a Lithium Ion Phosphate (LiFePO4) battery to power a hand held device. However every battery I found had this warning in the description: "This pack is for testing (prototype) only. It has not been UN38.3 tested yet." When I read further, it referred to UN shipping requirements. It also stated that this testing was available but was expensive. Batteryspace is only testing popular, non-custom battery packs at this time. So. The question is: right now I'm in the final stages of development, so the testing thing is ok. But when I go into production, I don't want to have the high expense of a UN38.3 test. At least not all on my own. So what options do we have? Just use a different type of battery instead, say NiMH?

Afro, isn't another concern for SLA batteries that they contain.. yknow, lead and sulfuric acid? Maybe not a concern for those small sealed ones, but the battery terminals around cars are often corroded or caked up with sulfate salts from leaking battery acid.

Another great thing about lead acids is their huge current capability, think a hundred amps for a car starter ;)

thanks

If I want to build portable power supply with your buck converter in the previous video, what battery should I use? The load might be around 5V @ 1.5A. cheers

Don't forget LSD (Pre-Charged) NiMh are incredibly tough, and more forgiving of overcharge, and over discharge than normal NiMh, due to their thicker separator.

My bike has a lifepo4 and has electric start. works well for now. Have a video of it.

I have a few phone batteries lying about, and I wanted to know how would I go about charging them without them blowing up. Can I just straightup connect the phone charger to the battery or would I need to build a protection circuit?

:) Thank You :)

Interested in learning about wireless power? Subscribers can get up to 80% off my course Wireless Power to the People - Wireless Charging 101 on udemy using the coupon code "KZfaq" www.udemy.com/wireless-power-to-the-people-wireless-charging-101/?couponCode=KZfaq

That awkward moment when you are from Romania, and the example for a lead-acid battery is a Rombat Cyclon

I have heard of rechargeable alkaline batteries. What's up with that? Is that another way of phrasing Nickel Metal Hydride batteries or is it Alkaline battery chemistry without the "you can't fully recharge a dead battery, only get closer, and even that is theoretical" part of it?

@6:26 @Afrotechmods Can't i just put a big capacitor in parallel to get along with the peak amps?

so buy bunch of panasonic eneloops, and ram them together to provide adequate power source except for devices that are design to be small and lightweight

5 star rating for this one

Nice video, only thing missing is the number of cycles.

How to chews a battery: Pikachu's diet digest.

Do you know if a lithium or alkaline battery's self discharge rate increases once the battery has been used? Does regular use of a battery impact the self discharge rate (vs. a battery sitting on a shelf)?

If you are in the EU use nkon to get your batteries, it's MUCH MUCH cheaper. They sell 2900mAh li-ion batteries for as low as €1,50 and they have really low shipping costs as well (for most orders only €4) It sounds too good to be true but it is not, I have bought a lot of batteries from them and they have all been good batteries (sony, panasonic, lg, samsung) with their specified capacity.

Tutorial on building protection circuits?

I have a device from which the new batteries are leaking after an hour of use. Namely 'smarty pad', 4 x AA batteries. Would you know why, and if it could be fixed? thanks.

First! And ; Intermission = Coffie time! woho!

I miss your content :\

What is the best type of batteries to operate a Thermoelectric module (TEC1-12706) ?

1:50 WIthout the Michal Bay Explosion!

For the lithium batteries, we should add discharge rate as a pro.

I thumb upped, because of that intermission, jfyi

Shipping companies specificity don't like lithium batteries. So getting them delivered to a country that doesn't manufacture lithium batteries can be quite a hassle.

Will it be okay if change my 3amp motorcycle battery to 6amp same size battery?

Explain the new batteries that don't explode please! :D

What kind of battery does a gopro use? Planning on buying a spare

Donated through PayPal. Thanks for the videos; keep 'em coming!

For a device consume 20Amp 12V what type of battery do you recommend as for portable device?

hey man,how can i charge an old laptop lithium ion battery which has a voltage of 3.1v when i took it out.(i know normally they have 3.7v)

The mayor downside of NiMh Batteries is, that they do not support high discharge currents, in contrast to Li-ion or Lead Acid Try to look up Peukert's Law for more information de.wikipedia.org/wiki/Peukert-Gleichung#Peukert-Zahl

i have a uranium battery pack for my pc in which i have seen your videos 😎😎

Lifepo4 batteries rule!

How did you measure the peak current of 1.1A?

What is the batteryspace.com equivalent for the EU?

Afrotechmods Hi, may I ask the amphere rating or C rating of 4 eneloop pro connect in series ? Was deciding between this config with a 1000mAh Li-Po @ 15C. not sure whether the eneloop would be enough to drive my dual motor project.